[Woodz428]

Although the information was a little lacking( what type heads,manifold, mileage etc.), I would start wondering about a blown head gasket. Pull the plugs and see if you see any coolant on them. If you do that would be where I'd start. If they are original heads and have been milled (maybe too much) you could have a cracked on. The previous ride may have escalated a developing problem. If they are aluminum heads, have they ever been retorqued?